An electronic device having a printed, circuit board (a base plate) and a connector is known in the art, for example, as disclosed in Japanese Patent Publication No. 2008-117675. The printed circuit board has multiple lands. The connector has a connector housing and multiple terminals supported by the connector housing. Each of the terminals is outwardly projected from a same terminal projecting surface of the connector housing and respectively connected to a corresponding land of the printed circuit board. The multiple terminals are arranged not only in a width direction of the connector housing but also in a height direction of the connector housing in a multiple-step form.
Each of the terminals is formed in an L-letter shape, which has a first terminal portion, a bent portion and a second terminal portion. The first terminal portion extends in a depth direction of the connector housing and a part of the first terminal portion is supported by the connector housing. The bent portion is connected to a back-side end of the first terminal portion. The second terminal portion extends from the bent portion in a direction to the printed circuit board and is electrically connected to the land.
As one of examples, two groups of the multiple terminals will be further explained, wherein each of first-group terminals and each of second-group terminals are arranged at a same position in the width direction of the connector housing but at different positions in the height direction of the connector housing. In such an example, the bent portion of the second-group terminal is located at a position, which is more separated from the printed circuit board in the height direction than that of the first-group terminal. In addition, the bent portion of the second-group terminal is located at a position of the depth direction of the connector housing, which is perpendicular to the width direction and the height direction, wherein the position of the bent portion of the second-group terminal is more separated in the depth direction away from the connector housing than that of the bent portion of the first-group terminal.
It is further known in the art that the above terminals may resonate with outside vibrations, for example, vibration of an internal combustion engine, vibration of a transmission apparatus of a vehicle and so on. Whether the terminal easily and/or strongly resonates with such outside vibration or not depends on an exposed length of the terminal, which is exposed to an outside of the connector housing. The exposed length of the terminal corresponds to a distance from a terminal projecting surface (a back-side surface) of the connector housing to the land of the printed circuit board. More exactly, the exposed length of the terminal is a sum of a projecting length and a connecting length of the terminal. The projecting length corresponds to a length of the first terminal portion between the terminal projecting surface of the connector housing and the bent portion of the terminal, while the connecting length corresponds to a length of the second terminal portion between the bent portion and the land of the printed circuit board.
In the above structure, the exposed length of the first-group terminal is smaller than that of the second-group terminal. More exactly, not only the projecting length of the first-group terminal is smaller than that of the second-group terminal, but also the connecting length of the first-group terminal is smaller than that of the second-group terminal.
As a result, even in a case that the exposed length of one of the first-group and the second-group terminals is designed so as not to resonate with the outside vibrations, the exposed length of the other terminal may have such a value that the terminal may resonate with the outside vibrations. Accordingly, it is difficult to design the exposed length of the first-group and the second-group terminals in such a way that neither the first-group terminal nor the second-group terminal may resonate with the outside vibrations.
The second-group terminal can be so modified that the exposed length of the second-group terminal becomes almost equal to that of the first-group terminal. For example, in the above case, the bent portion of the second-group terminal is located at a position, which is closer to the terminal projecting surface of the connector housing in its depth direction than that of the first-group terminal. Then, the projecting length of the second-group terminal can be made smaller than that of the first-group terminal, and thereby the exposed length of the second-group terminal becomes almost equal to that of the first-group terminal. However, according to such a modification, it is not possible to arrange the first-group and the second-group terminals at the same position in the width direction of the connector housing. In other words, the connector housing inevitably becomes larger in the width direction. Namely, a connector size is increased.